The cylinder lock has been in use for more than 100 years as a standard apparatus for locking doors and other items such as containers. In common use nowadays is the European double cylinder lock apparatus 30, also known as the ‘Haan’ profile lock, shown in prior art FIG. 1.
The double cylinder lock apparatus 30 pictured in FIG. 1, comprises a key 32, a double cylinder lock 34, and a cam 36. The standard components mounted on the cylinder lock 30 can be seen in FIG. 2, including a rotatable cylinder plug 35 (FIG. 1) that is fastened in place by circlips 38, and rotatable cam 36 having mounted inside it a coupling assembly 40. Additional standard components such as pins and springs are not shown.
The double cylinder lock apparatus 30 is operated as follows: the key 32 is rotated inside said cylinder lock 34 and the cam 36 is consequently rotated. In a mortise-type lock construction, for example, this rotation causes a displacement of a bolt (not shown) in the tangential direction to the motion of the cam 36. The displacement of the bolt causes it, for example, to enter or exit a door jamb (not shown), that results in locking or unlocking of the door. In summary, the prior art uses a rotational motion which is converted to tangential motion in order to move said locking bolt(s).
However, this is just one type of cylinder lock given as an example of the prior art. There are a multitude of variations of shapes and sizes of cylinder locks in existence.
Another prior art example is shown in FIG. 3, in which a double cylinder lock fitted with a gear 44 is shown, as described in my previous work as a co-inventor, in U.S. Pat. No. 3,991,595, issued Nov. 16, 1976. The difference between FIG. 1, and FIG. 3, is that instead of a cam 36 being utilized as in FIG. 1, a gear 44 is mounted to the cylinder lock 34. The primary advantage of operating a cylinder lock 34 fitted with a gear 44 is the reduced rotational force needed to move larger or multiple locking bolts. Instead of using a single rotation of the key to provide the required force for moving the bolt(s), gear 44 can be arranged to drive a reduction gear, thus enabling the user to move the bolt(s) more easily, thus distributing the force needed to move the bolt(s) over a longer distance.
Additionally it can be seen in FIG. 4, that the only component that has been changed from FIG. 2, is the gear 44. The circlips 38 and the coupling assembly 40 remain the same in both prior art examples.
In my previous work as a co-inventor, as described in U.S. Pat. No. 4,154,070 issued May 15, 1979, a lock was disclosed that causes insertion of multiple bolts into the jamb surrounding the door in multiple directions. The disadvantage of this design is that in order to install the device, a large section of the door interior volume needs to be removed, which is a difficult, time consuming and expensive process. In addition, the door structure itself is substantially weakened, reducing overall security. The lock is made of thin sheet metal and is not strong enough.
Therefore, it would be desirable to provide an improved cylinder lock enabling design of more compact locks, with stronger materials, manufactured by advanced production technologies, at a reasonable price. The compact design will enable installation of the locks with minimal interference to the structural integrity of the door while at the same time utilizing components of the standard cylinder locks in use and in production around the world.